Young duo Nathan Ake and Nathaniel Chalobah were also sold, while Abraham was also not kept on despite impressing on loan at Bristol City last season.

The 20-year-old scored 26 goals in all competitions for the Championship club, prompting talk that he could be ready to make an impact at Stamford Bridge.

However, Chelsea don’t have the best track record of handing opportunities out to their academy products, and few were too shocked when Abraham was instead sent on loan to the Liberty Stadium for the season.

Now with Alvaro Morata’s recent injury problems and Michy Batshuayi’s lack of form, Lampard has criticised the decision to let the young forward go for the length of the campaign.

‘For Chelsea as a club, yes it is a mistake,’ Lampard told BT Sport, as quoted by the Metro.

‘It’s not (a mistake) for Tammy as I don’t think he would have played so many games. Now you see him playing regularly and he is improving as a player.

‘Chelsea could say “we didn’t feel Tammy was going to play”. If you say Morata was fit all season then it is great experience for him and he comes back next season as a well-rounded player.

‘But now Morata is injured it seems a mistake. You can’t have it both ways. I know I’ve sat on the fence there but you improve the individual by sending him on loan, but as a club now you go “maybe we could have kept him”.’